The Kell Hounds were born even before Morgan and Patrick had thoughts of running their own mercenary command. Arthur Luvon, future husband of Lyran ArchonKatrina Steiner and Morgan and Patrick's cousin, dubbed the two brothers the Kell Hounds after witnessing them as young boys running around and terrorizing a neighbor's flock of sheep. Arthur drew up the Kell Hounds' crest and predicted that the two would grow up to become great MechWarriors. When Arthur died, Morgan and Patrick used the money left to them to form the Kell Hounds mercenary unit which they created in 3010. Though initially mocked as rich boys playing mercenary, the two made quite the impression with their surprisingly advanced grasp of strategy and tactics, as well as a top-notch technical support staff.

During the Third Succession War, the Kell Hounds were sent to the planet of Mallory's World, where Prince Ian Davion of the Federated Suns was engaged in a running battle with Yorinaga Kurita and his Second Sword of Light regiment. Prince Davion was killed in a rear-guard action and would have been taken as a trophy by Yorinaga had Morgan Kell not intervened. In one of the most celebrated, and mysterious, battles of all time, Morgan challenged Yorinaga to a duel that would decide the victor of Mallory's World. The battle between these two elite MechWarriors became a deadly game of cat and mouse, with Morgan's more agile Archer feinting and striking against Yorinaga's more powerful Warhammer. Yorinaga seemed to gain the upper hand when a blast from his PPC destroyed the Archer's right arm. With the Archer on its knees, Yorinaga moved in to deliver the final blow. At this point, however, by all accounts Morgan's Archer disappeared from the battle computers of every 'Mech present; the computers would just not acknowledge the 'Mech as a target. Thus, at point-blank range, Yorinaga managed to fire, and miss, with all the weapons at his disposal. In disbelief Yorinaga fired again and again, each time missing the Archer which was just a few meters away. In the midst of this firestorm, Morgan managed to bring his 'Mech upright and bow towards Yorinaga. At this Yorinaga paused, uttered a haiku, and finally ordered his unit to pull back. The Kell Hounds had carried the day in a most extraordinary fashion.

The mysterious conclusion of this duel became known as the Phantom 'Mech, and became a legend throughout the Inner Sphere.

Following the campaign on Mallory's World, Morgan did the totally unexpected: He largely disbanded the Kell Hounds, sending off two-thirds of the regiment and leaving his brother Patrick with only a mixed battalion of 'Mechs and supporting vehicles. Morgan himself went into exile, hiding away on the religious retreat of Zaniah III. All of this without word or rhyme to any of the remaining Kell Hounds and, most cruelly in the eyes of those left behind, without any explanation to Patrick.

Reduced down to the level of a reinforced battalion after what the remaining Kell Hounds had dubbed "The Defection," the unit was entering its darkest days. But Patrick, taking the rank of Lieutenant-Colonel as he believed Morgan to still be the commanding officer of the Kell Hounds, was determined to make the new Kell Hounds the best battalion-level mercenary unit out there. Their next contract was a pirate-hunting mission on the fringes of the Free Worlds League. Eventually, the Kell Hounds found themselves employed by the Lyran Commonwealth again to garrison duty on the planet of Pacifica. When the Draconis Combine got word of this, a task force was covertly sent to destroy the Kell Hounds.

The Hounds beat off the first few attempts, though Patrick was critically wounded. Soon, however, they found their situation untenable. Getting off-planet and jumping into Combine space, the Kell Hounds found themselves at a former mining outpost called Styx. Unbeknownst to the Kell Hounds, the DropShipSilver Eagle, carrying Archon-designate Melissa Steiner on a covert mission to meet her future husband Hanse Davion, had been hijacked and taken to Styx by the local Heimdall cell. To make matters worse, the Combine had gotten wind of this and sent the newly formed Genyosha with Yorinaga Kurita at its head to capture Melissa. Only when lead elements of the Kell Hounds made their way partly through the Styx compound, and had come across Melissa themselves, did they come to understand the gravity of the situation.

Tricking the Kuritans into thinking that they had already taken Melissa off-planet, the Kell Hounds waited for Patrick's cue to engage the Genyosha, which came in the form of Patrick dropping his Victor right in the midst of the Kuritans despite his previous injuries. As the rest of the Kell Hounds attacked, Patrick made it his sole duty to reduce the numerical superiority of the Genyosha despite murderous fire coming from Yorinaga's Warhammer. The battle came to an end when Yorinaga destroyed Patrick's Victor, and in return Captain Daniel Allard rammed his Valkyrie into the back of Yorinaga's Warhammer. With the Genyosha in retreat, the Kell Hounds had saved Melissa Steiner but at a great cost: Patrick Kell died from his wounds, safe in the knowledge that he had done his duty.

Following the death of Patrick Kell, Morgan returned from exile and recalled those former Kell Hounds that he had previously sent away. Back up to regimental strength, Morgan set the Kell Hounds on a path of vengeance against Yorinaga Kurita even as the Fourth Succession War broke out across the Inner Sphere. The first meeting between the Hounds and Yorinaga's Genyosha was technically on the planet of Northwind. Major Scott Bradley, one of those Kell Hounds who left under Morgan's orders, petitioned Morgan to fold his Bradley's Bravos into the Kell Hounds and was thus allowed to designate his unit as the Kell Hound's Third 'Mech Battalion. Thus when the Draconis Combine launched an invasion of Northwind, the Genyosha was among the invading forces.

While the Genyosha were on Northwind Morgan took the Kell Hounds proper to Nashira, the homeworld of the Genyosha. Not finding them there, Morgan instructed the civilians to vacate the Genyosha's command post and to take as many of the Genyosha's personal effects along with them before his Hounds leveled the command post. In this way Morgan sought to distinguish this fight as one between him and Yorinaga alone. To arrange a proper meeting between the two, Morgan created a large star map out of the rubble of the command post, indicating that Morgan and Yorinaga should decide their fate on the planet of Ryde.

During the War of 3039, the Hounds were based in along the Federated Commonwealth's Terran Corridor, which Hanse Davion hoped would be a deterrent against Kurita counter-attacks. However, he was forced to relocate them to Robinson when that world was threatened.

In 3040, Katrina Steiner died, leaving the Hounds enough money in a bequest to form a second regiment. Morgan Kell promoted Daniel Allard to command the first regiment and Scott Bradley to command the second.[1]

The Kell Hounds were one of the first House units (contracted by the Free Rasalhague Republic) to face the Clans. In 3049, the Kell Hound's Third Battalion fought a running battle with elements of Clan Wolf on The Rock while hunting pirates who used the planet as their base of operations. Though the Hounds fought with their typical skill and tenacity, they were no match for the superior weaponry and skill of the Clan pilots; eventually the entire battalion was destroyed. However, Phelan Kell, son of Morgan, would be taken captive by the Wolves and rise through the ranks of the Wolf Clan to eventually stand as one of their Khans.

Despite their initial losses, the Hounds would participate in two major victories against the Clans. The first was in the liberation of Twycross, when they and elements from the Federated Commonwealth wrested control of the planet from Clan Jade Falcon. Though a costly battle, it served as a great morale boost for the entire Inner Sphere as it proved that the Clans could be beaten. The Hounds also played a crucial role during the Battle of Luthien, where Clans Smoke Jaguar and Nova Cat attempted to decapitate the Draconis Combine in one fell swoop. During that battle, the Hounds along side Wolf's Dragoons and elite units of the Combine helped turn the invaders from the Draconis Combine's capital. Following that battle, Coordinator Takashi Kurita rescinded his "Death to Mercenaries" order.

On August 28th, 3073, 1st Regiment was attacked on New Exford by the Word of Blake's 50th Shadow Division. The Kell Hounds' aerospace assets were not adequate enough stop the 50th from landing. The 2nd Battalion attempted to flank the incoming force, but were themselves completely annihilated. This left the remaining two battalions to defend their base. The Regiment's temporary commanding officer, Christian Kell was killed by head hunter units sent from the 50th, causing the remaining Kell Hounds to fall back. The unit suffered 70% losses by the time the unit was able retreat.[7]

In 3081, the Kell Hounds were a defiant but small remnant of their pre-Jihad strength. The Kell Hounds had lost Daniel Allard to the Jade Falcons in 3069, after which Akira Brahe had taken charge; this was followed by the departure of the Crescent Hawks, who left the Kell Hounds after the campaign to liberate Tharkad. The Kell Hounds had already been badly wounded as a result of the battles on New Exford by the time the campaign to liberate Terra began, but would suffer their heaviest losses in the battle for Cairo. The Word of Blake forces caught the Hounds in a brutally effective trap which reduced more than a regiment of elite mercenaries to a bare four lances of 'Mechs. Despite what would appear to be crushing losses, the surviving Kell Hounds refused to give up, regrouped and began to rebuild on Arc-Royal.[8]

In 3085 Clan Wolf-in-Exile demonstrated that they considered the Kell Hounds to still be strong allies by gifting them with "Allard's Revenge", a brand new Arctic Wolf IIOmniMech in Kell Hounds colors. This gift, given at a time when the Arctic Wolf II had yet to be issued in any numbers outside the Clan's Alpha Galaxy was a strong signal to those watching of the close ties between the two.[9] It would take until 3095 for the Kell Hounds to finally finish rebuilding after the losses of the Jihad.[10]

The mid-thirty-second century was a time of ferocious combat and heavy losses for the Kell Hounds as warfare rapidly engulfed the Inner Sphere. On the 15th of August 3142[11] the Kell Hounds were mounting a ferocious defense of Timkovichi against the forces of Malvina Hazen and her Golden Ordun. The massed light forces of the Golden Ordun and the three-pronged attack into the Commonwealth had seen the defending Commonwealth forces pinned in place, with many units overwhelmed, but the Kell Hounds were one of the tough, experienced mercenary units skilled in combined-arms warfare that proved a match for Malvina's forces.[12] The Jade Falcons were forced to resort to subjecting the Hounds to orbital bombardment[12][11] from the Aegis-class heavy cruiser CJF Red Talon[13] to defeat them, one of a number of savage, extreme actions that Jade Falcons relied on - along with their sheer numbers - to generate tales of terror sufficient to intimidate worlds into surrendering without the need for a military campaign.[12] Unfortunately for Hazen's allies in Clan Hell's Horses, the orbital bombardment that virtually annihilated the Hounds also savaged the Horses' Beta Galaxy, forcing the Horses to rotate the remains of the Galaxy back into their Occupation Zone to seed new Horde Clusters.[14]

On the 1st of November 3143Callandre Kell assembled a battalion-strong force of Kell Hounds and struck deeply into the Jade Falcon Occupation Zone, an act of revenge against the Falcons for their actions on Timkovich. Accompanying the Hounds on their campaign was the heir to the Federated Suns, Julian Davion, who took a leave of absence from the First Davion Guards to join the campaign, leaving the Guards in Commonwealth space and under the direct command of Trillian Steiner.[15]

Julian Davion would remain with Callandre and the Hounds for more than a year, only beginning preparations to leave in October 3144, after the Hounds had defeated the Clan Hell's Horses forces on Porrima.[15] The Kell Hounds continued to harass the Jade Falcons after Julian's departure, targetting worlds recently occupied by the Falcons; their repeated attacks have left those worlds restless, stretching the Falcon forces and Watch and making the worlds not just unproductive but an actual drain on the Jade Falcon's resources.[16] The ongoing successes earned by the Kell Hounds were actually causing problems for their allies, Clan Wolf-in-Exile; with the Lyran Commonwealth offering fortunes to recruit personnel and units for the desperate defense of the Commonwealth and the Kell Hound name ringing loudly in the ears of the civilian population as Calliandre Kell continues to mount aggressive, glorious attacks on the Jade Falcons, the number of volunteers willing to fight for the Wolves was steadily dropping.[17]

Reports in 3145 indicated that the bitter campaign against the Jade Falcons was exacting a toll on the Hounds, with the unit suffering badly from fatigue and battle damage. Despite that, the Hounds remained an elite, heavily experienced unit, heavily upgraded with some of the best technology available anywhere.[10]

The Kell Hounds have two reinforced 'Mech regiments, each with their own complement of AeroSpace Fighters and infantry. The Hounds also employ a command lance for the entire unit, which is never included in any contract; however, the Kell Hounds reserve the right to deploy the command lance with any of its units in the field.

Though Morgan is officially retired, he is still regarded as the supreme commander of the Kell Hounds; as such, Daniel Allard (overall unit commander), Akira Brahe (First Regiment commander), and Scott Bradley Jr. (Second Regiment commander) have taken the rank of lieutenant-colonel out of respect for Morgan.

Caitlin Kell retired in 3104, passing command of the Kell Hounds to Maria Allard, the great-grandaughter of Morgan Kell, and Maria would remain in command of the Hounds until her death in combat on Dustball in 3122. With Maria's death, Evan Kell assumed command of the Hounds, commanding until his death in the CJF Red Talon's orbital bombardment of Timkovichi in 3142, at which point command of the surviving elements of the Hounds passed to Callandre Kell.[10]

The Kell Hounds appear in the MechWarrior 4: Mercenaries PC game as potential sponsors, employers (New Exford), and allies (Tharkad). Units sponsored by the Kell Hounds have earlier access to Clan tech, though not as early as Wolf's Dragoons who start the game with it.